I am not convinced of the entire thing, but some comments:
-election results: CDU would probably do better in Eastern germany, the SPD worse, they don't have a party organisation any more
-Gustav Heinemann: To early for him to be back in the big game, he had just left the CDU, and started his own party for the 1953 election, with a unification there really is no reason for him to become a Social Democrat
-Ludwig Erhard as Bundespräsident? He would be a great Simbol, but I doubt that he would have wanted the job
Unification wouldn't go as fast as in OTL 1990, there would likely be a national assembly for a Constitution, that would have to include the new borders and a referendum, who knows what woulld happen.
A treaty should include a settlement for German POWs and a UN membership.
Germany might be allowed millitarry partnership with other neutrual contries, like Switzerland, Austria, Sweden or even Yugoslavia...
And I think, the status of Sahrland should be settled as well, no reason to leave that open.